CODEWITHSUNDEEP
javaoverridingequals
Philémon Roubaud
Philémon Roubaud

Reputation: 57

Override equals method in java

Let's consider the following simple class.

class Point {
private float x;
private float y;

public Point(float x, float y){
    this.x=x;
    this.y=y;
}

public float getX(){return this.x;}
public float getY(){return this.y;}
public void setX(float x){this.x=x;}
public void setY(float y){this.y=y;}

@Override
public String toString(){
    return ("x = "+this.x+", y = "+this.y+";");
}
@Override
public Point clone(){
    return new Point(this.x,this.y);
}
@Override
public boolean equals(Object object){
    if (object != null && object.getClass()==Point.class){
        return object.getX()==this.x && object.getY()==this.y;
    }
    else{
        return false;
    }
}

The problem is in the rewrite of method equals: I use the general Object class as attribute to make it more flexible, but netbeans prints error on return line: "Object has no method getX" which is perfectly logical.

But the problem is still here, how can I manage to fix this?

Thanks you in advance

Upvotes: 1

Views: 66

Answers (1)

markspace
markspace

Reputation: 11020

This is pretty simple but you need to cast object:

@Override
public boolean equals(Object object){
    if (object != null && object.getClass()==Point.class){
        Point p = (Point)object;
        return p.getX()==this.x && p.getY()==this.y;
    }
    else{
        return false;
    }
}

This is also relevant: Casting in equals method

Upvotes: 3

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